Barbituric acid (CAS # 67-52-7, CAS name: 2,4,6(1H,3H,5H)-pyrimidinetrione) and its derivatives possess useful pharmacological properties, including anti-convulsant, anti-anxiety and muscle relaxant activities. In addition, many barbituric acid derivatives further possess sedative and/or hypnotic activities, which makes the compounds disadvantageous for patients who wish to maintain mental acuity.
1,3-bis(methoxymethyl)-5,5-diphenylbarbituric acid is a barbituric acid derivative that possesses anti-convulsant, anti-anxiety and muscle relaxant activities, but does not possess major sedative or hypnotic activities. As such, the compound is considered to be a promising candidate for patients who wish to maintain mental acuity.

U.S. Pat. No. 4,628,056 (the '056 patent) discloses a process for preparing 1,3-bis(methoxymethyl)-5,5-diphenylbarbituric acid, wherein 5,5-diphenylbarbituric acid is reacted with sodium hydride and chloromethyl methyl ether. The reaction results in the addition of two methoxymethyl groups to the 5,5-diphenylbarbituric acid to form 1,3-bis(methoxymethyl)-5,5-diphenylbarbituric acid.
1-methoxymethyl-5,5-diphenylbarbituric acid is an analog of 1,3-bis(methoxymethyl)-5,5-diphenylbarbituric acid that is believed to possess a similar spectrum of activity. Thus, 1-methoxymethyl-5,5-diphenylbarbituric acid is believed to possess anti-convulsant, anti-anxiety and muscle relaxant activities, without possessing major sedative or hypnotic activities, and is similarly considered to be a promising candidate for patients who wish to maintain mental acuity.

U.S. Pat No. 6,093,820 discloses a two step process for preparing 1-methoxymethyl-5,5-diphenylbarbituric acid, in which 5,5-diphenylbarbituric acid is first reacted with excess sodium hydride, and then reacted with methoxymethyl methanesulfonate. As in the '056 patent process for preparing 1,3-bis(methoxymethyl)-5,5-diphenylbarbituric acid, the '820 patent process utilizes 5,5-diphenylbarbituric acid as a starting material, but only one methoxymethyl group is added, not two. The '820 patent further discloses a pharmaceutical formulation of 1-methoxymethyl-5,5-diphenylbarbituric acid for treating convulsions, seizures, muscle stiffness, nervous strain and anxiety.
There is a continuing need for a process for preparing 1-methoxymethyl-5,5-diphenylbarbituric acid.